The technology, developed by a former Royal Marine commando, temporarily impairs the vision of anyone who looks towards the source.

It has impressed a division of the Home Office which is testing a new range of devices because of the growing number of violent situations facing the police.

The developer, British-based Photonic Security Systems, hopes to offer the device to shipping companies to deter pirates. Similar devices have been used by ISAF troops in Afghanistan to protect convoys from insurgents.

The laser, resembling a rifle and known as an SMU 100, can dazzle and incapacitate targets up to 500m away with a wall of light up to three metres squared. It costs £25,000 and has an infrared scope to spot looters in poor visibility.

Looking at the intense beam causes a short-lived effect similar to staring at the sun, forcing the target to turn away.